The present invention relates to how enterprise networks can secure their Internet Protocol (IP) traffic using IP Security (IPSec) when that IP traffic is routed over resilient Multi-Protocol Layer Switching (MPLS) Layer 3 Virtual Private Networks (VPNs), also called IP VPNs.
Enterprise networks have been connecting their remote sites using BGP/MPLS IP Virtual Private Networks (VPNs) as defined in the IETF Request For Comment (RFC) 4364, as provided to them by service providers. Enterprise networks have been using those Multi-Protocol Layer Switching (MPLS) networks with different network redundancy scenarios, where Customer Edge (CE) routers can be redundant and/or service Providers Edge (PE) routers can also be redundant.